PointLight Node

If you're new to lighting in VRML, there is a Lighting section in this tutorial which discusses general features of lighting in VRML. In here only the aspects which are particular to Point Lights are discussed.

Point Lights define a light source in a specified location. The light rays from this type of lights go in all directions. This implies that, as opposed to Directional Lights, Point Lights have a location but not a direction field. The following figure attempts to define a Point Light graphically (the point where the light rays start is the light location.

This light lits all nodes regardless of their position in the file, i.e. this light is not scoped. There is however a way of limiting the volume which is lit by this light, one can specify a radius which defines the maximum distance that the light rays can travel. Objects which are further away from the light source than the radius are not lit by the light source.

There is still another way to control the attenuation within the sphere defined by the radius. Using the attenuation field one can specify how the light grows dimmer with distance, within the sphere defined by the radius.

The following fields are present in this node:

on specifies if the light is active. This is a boolean field.

intensity has values between 0.0 and 1.0. Higher values specify stronger lights.

ambientIntensity specifies how much this light contributes to the overall lighting .Values must be between 0.0 and 1.0

color is a RGB field to specify the color of the light..

location which specifies a vector in 3D defining the coordinates of the light in your world.

attenuation is a 3D vector that specifies how the light looses its intensity as distance from the light source increases. All vector values must be greater than or equal to zero

radius specifies the maximum distance for the light rays to travel. Must be greater than or equal to zero.

Syntax:

PointLight {

on TRUE

intensity 1

ambientIntensity 0

color 1 1 1

location 0 0 0

attenuation 1 0 0

radius 100

}

Note: On the VRML world presented as example the sphere is placed at -2.5 0 0, the cone is placed at the origin, and the cylinder is placed at 2.5 0 0. If you're not familiar with placing shapes other than at the origin see the Transform node.